In residential or commercial construction, precisely determining a reference point on one side of a structure such as a wall, floor or ceiling from an opposite side of the structure is required to avoid unnecessary trial and error as well as damage to the structure. For example, when installing a ceiling fan, a workman must know exactly where to cut a hole on the one side of the ceiling in order to line up with an incoming conduit on the opposite side of the ceiling, in an attic for instance, without cutting into a truss or beam. Likewise, if the workman cuts from the attic side without a precise reference point, the hole for the ceiling fan may be off-center in the room below. By way of further example, a customer will request that a cable or satellite television technician drill a hole from outside of the customer's house so that a television cable can be routed into a lower corner of a room to be as unobtrusive as possible. Unfortunately, most installation technicians do not have the time or tools to make precision measurements and their cable installations are often unsatisfactory.
Reference points are determined and marked usually by making a number of measurements on one side of the structure and then repeating the measurements on the opposite side of the structure. A hole is then drilled that extends from one side of the structure to the other side of the structure. This approach has several drawbacks. Foremost, manual measurements are time consuming due to the large number of measurements that must be made and due to the difficulty in transferring those measurements to the opposite side of the structure. This approach often leads to numerous unnecessary holes being drilled that of course must be patched or repaired to return the structure to its original condition. Ironically, the unnecessary holes are often due to the multiple measurements, which are meant to provide precision but can be confusing and lead to mismarked reference points. Moreover, this conventional measurement approach is costly due to the time associated with performing the initial measurements as well as the time and cost associated with patching or otherwise repairing the unnecessary holes.
Various devices available in the market have attempted to automate measurement processes or electronically locate reference points for cutting or drilling from blind sides of structures. However, these devices tend to be bulky and excessively complex, especially for a layman for use in a home project. Moreover, for an occasional home project, the existing devices can be cost prohibitive.